1,862 research outputs found
Transcriptome-wide analysis reveals different categories of response to a standardised immune challenge in a wild rodent
Individuals vary in their immune response and, as a result, some are more susceptible to infectious disease than others. Little is known about the nature of this individual variation in natural populations, or which components of immune pathways are most responsible, but defining this underlying landscape of variation is an essential first step to understanding the drivers of this variation and, ultimately, predicting the outcome of infection. We describe transcriptome-wide variation in response to a standardised immune challenge in wild field voles. We find that markers can be categorised into a limited number of types. For the majority of markers, the response of an individual is dependent on its baseline expression level, with significant enrichment in this category for conventional immune pathways. Another, moderately sized, category contains markers for which the responses of different individuals are also variable but independent of their baseline expression levels. This category lacks any enrichment for conventional immune pathways. We further identify markers which display particularly high individual variability in response, and could be used as markers of immune response in larger studies. Our work shows how a standardised challenge performed on a natural population can reveal the patterns of natural variation in immune response
Two in one: cryptic species discovered in biological control agent populations using molecular data and crossbreeding experiments
There are many examples of cryptic species that have been identified through DNA-barcoding or other genetic techniques. There are, however, very few confirmations of cryptic species being reproductively isolated. This study presents one of the few cases of cryptic species that has been confirmed to be reproductively isolated and therefore true species according to the biological species concept. The cryptic species are of special interest because they were discovered within biological control agent populations. Two geographically isolated populations of Eccritotarsus catarinensis (Carvalho) [Hemiptera: Miridae], a biological control agent for the invasive aquatic macrophyte, water hyacinth, Eichhornia crassipes (Mart.) Solms [Pontederiaceae], in South Africa, were sampled from the native range of the species in South America. Morphological characteristics indicated that both populations were the same species according to the current taxonomy, but subsequent DNA analysis and breeding experiments revealed that the two populations are reproductively isolated. Crossbreeding experiments resulted in very few hybrid offspring when individuals were forced to interbreed with individuals of the other population, and no hybrid offspring were recorded when a choice of mate from either population was offered. The data indicate that the two populations are cryptic species that are reproductively incompatible. Subtle but reliable diagnostic characteristics were then identified to distinguish between the two species which would have been considered intraspecific variation without the data from the genetics and interbreeding experiments. These findings suggest that all consignments of biological control agents from allopatric populations should be screened for cryptic species using genetic techniques and that the importation of multiple consignments of the same species for biological control should be conducted with caution
A candidate tolerance gene identified in a natural population of field voles (Microtus agrestis)
The animal immune response has hitherto been viewed primarily in the context of resistance only. However, individuals, can also employ a tolerance strategy to maintain good health in the face of on-going infection. To shed light on the genetic and physiological basis of tolerance, we use a natural population of field voles, Microtus agrestis, to search for an association between the expression of the transcription factor Gata3, previously identified as a marker of tolerance in this system, and polymorphism in 84 immune and non-immune genes. Our results show clear evidence for an association between Gata3 expression and polymorphism in the Fcer1a gene, with the explanatory power of this polymorphism being comparable to that of other non-genetic variables previously identified as important predictors of Gata3 expression. We also uncover the possible mechanism behind this association using an existing protein-protein interaction network for the mouse model rodent, Mus musculus, which we validate using our own expression network for M. agrestis. Our results suggest that the polymorphism in question may be working at the transcriptional level, leading to changes in the expression of the Th2-related genes, Tyrosine-protein kinase BTK and Tyrosine-protein kinase TXK, and hence potentially altering the strength of the Th2 response, of which Gata3 is a mediator. We believe our work has implications for both treatment and control of infectious disease
A high incidence of vertebral fracture in women with breast cancer
Because treatment for breast cancer may adversely affect skeletal metabolism, we investigated vertebral fracture risk in women with non-metastatic breast cancer. The prevalence of vertebral fracture was similar in women at the time of first diagnosis to that in an age-matched sample of the general population. The incidence of vertebral fracture, however, was nearly five times greater than normal in women from the time of first diagnosis [odds ratio (OR), 4.7; 95% confidence interval (95% CI), 2.3–9.9], and 20-fold higher in women with soft-tissue metastases without evidence of skeletal metastases (OR, 22.7; 95% CI, 9.1–57.1). We conclude that vertebral fracture risk is markedly increased in women with breast cancer. © 1999 Cancer Research Campaig
The impact of ocean acidification on the functional morphology of foraminifera
This work was supported by the NERC UK Ocean Acidification Research Programme grant NE/H017445/1. WENA acknowledges NERC support (NE/G018502/1). DMP received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland). MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions.Culturing experiments were performed on sediment samples from the Ythan Estuary, N. E. Scotland, to assess the impacts of ocean acidification on test surface ornamentation in the benthic foraminifer Haynesina germanica. Specimens were cultured for 36 weeks at either 380, 750 or 1000 ppm atmospheric CO2. Analysis of the test surface using SEM imaging reveals sensitivity of functionally important ornamentation associated with feeding to changing seawater CO2 levels. Specimens incubated at high CO2 levels displayed evidence of shell dissolution, a significant reduction and deformation of ornamentation. It is clear that these calcifying organisms are likely to be vulnerable to ocean acidification. A reduction in functionally important ornamentation could lead to a reduction in feeding efficiency with consequent impacts on this organism’s survival and fitness.Publisher PDFPeer reviewe
Undergraduate medical textbooks do not provide adequate information on intravenous fluid therapy: a systematic survey and suggestions for improvement
<b>Background</b><p></p>
Inappropriate prescribing of intravenous (IV) fluid, particularly 0.9% sodium chloride, causes post-operative complications. Fluid prescription is often left to junior medical staff and is frequently poorly managed. One reason for poor intravenous fluid prescribing practices could be inadequate coverage of this topic in the textbooks that are used.<p></p>
<b>Methods</b><p></p>
We formulated a comprehensive set of topics, related to important common clinical situations involving IV fluid therapy, (routine fluid replacement, fluid loss, fluids overload) to assess the adequacy of textbooks in common use. We assessed 29 medical textbooks widely available to students in the UK, scoring the presence of information provided by each book on each of the topics. The scores indicated how fully the topics were considered: not at all, partly, and adequately. No attempt was made to judge the quality of the information, because there is no consensus on these topics.<p></p>
<b>Results</b><p></p>
The maximum score that a book could achieve was 52. Three of the topics we chose were not considered by any of the books. Discounting these topics as “too esoteric”, the maximum possible score became 46. One textbook gained a score of 45, but the general score was poor (median 11, quartiles 4, 21). In particular, coverage of routine postoperative management was inadequate.<p></p>
<b>Conclusions</b><p></p>
Textbooks for undergraduates cover the topic of intravenous therapy badly, which may partly explain the poor knowledge and performance of junior doctors in this important field. Systematic revision of current textbooks might improve knowledge and practice by junior doctors. Careful definition of the remit and content of textbooks should be applied more widely to ensure quality and “fitness for purpose”, and avoid omission of vital knowledge
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"Am iz kwiin" (I'm his queen): Combining interpretative phenomenological analysis with a feminist approach to work with gems in a resource-constrained setting
This article focuses on working with gems using a feminist approach to interpretative phenomenological analysis (IPA) in a resource-constrained setting. The research explores the experiences of maternal disclosure of HIV to children of HIV positive mothers in Kingston, Jamaica. A feminist approach helps recognise power imbalances within research relationships and the women’s lived experiences. We present three “gems” which illuminate women’s lived experiences and explore how popularised representations of women’s sexuality and mothering influence disclosure discourses. We use emotion work as a conceptual resource to structure the women’s narratives and challenge existing policy discourses, which arguably represent disclosure within a binary, rationalist, decision-making framework. This article adds to global literature on maternal HIV disclosure and problematises policy discourses by bringing into relief the emotion work women engage in when deciding if and how to communicate their HIV status to their children. It adds to the body of research using IPA, particularly in resource-constrained settings where IPA has thus far had little application
mRNA profiling of the cancer degradome in oesophago-gastric adenocarcinoma.
BACKGROUND: Degradation of the extracellular matrix is fundamental to tumour development, invasion and metastasis. Several protease families have been implicated in the development of a broad range of tumour types, including oesophago-gastric (OG) adenocarcinoma. The aim of this study was to analyse the expression levels of all core members of the cancer degradome in OG adenocarcinoma and to investigate the relationship between expression levels and tumour/patient variables associated with poor prognosis. METHODS: Comprehensive expression profiling of the protease families (matrix metalloproteinases (MMPs), members of the ADAM metalloproteinase-disintegrin family (ADAMs)), their inhibitors (tissue inhibitors of metalloproteinase), and molecules involved in the c-Met signalling pathway, was performed using quantitative real-time reverse transcription polymerase chain reaction in a cohort of matched malignant and benign peri-tumoural OG tissue (n=25 patients). Data were analysed with respect to clinico-pathological variables (tumour stage and grade, age, sex and pre-operative plasma C-reactive protein level). RESULTS: Gene expression of MMP1, 3, 7, 9, 10, 11, 12, 16 and 24 was upregulated by factors >4-fold in OG adenocarcinoma samples compared with matched benign tissue (P<0.01). Expression of ADAM8 and ADAM15 correlated significantly with tumour stage (P=0.048 and P=0.044), and ADAM12 expression correlated with tumour grade (P=0.011). CONCLUSION: This study represents the first comprehensive quantitative analysis of the expression of proteases and their inhibitors in human OG adenocarcinoma. These findings implicate elevated ADAM8, 12 and 15 mRNA expression as potential prognostic molecular markers
Mathematics difficulties in extremely preterm children : evidence of a specific deficit in basic mathematics processing
Background:
Extremely preterm (EP, <26 wk gestation) children have been observed to have poor academic achievement in comparison to their term-born peers, especially in mathematics. This study investigated potential underlying causes of this difficulty.
Methods:
A total of 219 EP participants were compared with 153 term-born control children at 11 y of age. All children were assessed by a psychologist on a battery of standardized cognitive tests and a number estimation test assessing children’s numerical representations.
Results:
EP children underperformed in all tests in comparison with the term controls (the majority of Ps < 0.001). Different underlying relationships between performance on the number estimation test and mathematical achievement were found in EP as compared with control children. That is, even after controlling for cognitive ability, a relationship between number representations and mathematical performance persisted for EP children only (EP: r = 0.346, n = 186, P < 0.001; control: r = 0.095, n = 146, P = 0.256).
Conclusion:
Interventions for EP children may target improving children’s numerical representations in order to subsequently remediate their mathematical skills
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